The New York Rangers selected Stephane Brochu in the ninth round of the 1985 NHL Entry Draft, 175th overall. He is also a member of the NHL's One-Game Wonder Club.

Brochu played three years of major junior hockey in the QMJHL, starting with the Quebec Remparts in 1984-85. In 59 games, he found the back of the net on two occasions while tallying 18 points. The following year he greatly improved on his offensive statistics, scoring 14 goals and 41 points as a member of the St. Jean Beavers. During his final year with the Beavers in 1987-88 he played in 29 games, scoring four goals and 39 points. He also played 52 games with the IHL's Colorado Rangers.

He returned to Denver in 1988-89 playing in67 games for the Rangers. It was also the year he played his one and only NHL game, dressing for the New York Rangers.

Although Brochu never again played in the NHL, his pro hockey career continued for another 12 years with the Fort Wayne Comets, Kansas City Blades, Detroit Vipers and Chicago Wolves of the IHL, Flint Bulldogs and Flint Generals and Adirondack Icehawks of the UHL and the Adirondack Red Wings of the AHL. His final pro season was in 2000-01 when he played 17 games with the Flint Generals.